Apparatus for dry cleaning of fabrics in situ

ABSTRACT

Apparatus for dry cleaning of fabrics and textiles without collection, purifying, and/or recirculation of the used solvent.

United States Patent [191 Mooring June 11, 1974 APPARATUS FOR DRY CLEANING O FABRICS IN SITU [75] Inventor: Scott W. Mooring, Fort Worth, Tex.

[73] Assignee: Steamatic, Inc., Ft. Worth, Tex.

[22] Filed: Feb. 16, 1972 [211 App]. No.: 226,697

Related U.S. Application Data [63] Continuation-impart of Ser. No. 206,059, Dec. 8,

1971, abandoned.

[52] U.S. Cl. 15/321 [51] Int. Cl A471 7/00 [58] Field of Search 15/314, 321, 353; 68/20 [56] References Cited UNITED STATES PATENTS 2,499,876 3/1950 Platek 15/353 X 2,533,395 12/1950 Paine 15/353 X 2,549,181 4/1951 Durham 15/353 X 3,262,146 7/1966 Hays 15/321 3,562,844 2/1971 Thompson et a1. 15/321 X 3,663,984 5/1972 Anthony Ct a1 15/321 Primary Examiner-Harvey C. Hornsby Assistant Examiner-C. K. Moore Attorney, Agent, or Firm-Bertram H. Mann; Frank B. Pugsley [57] ABSTRACT Apparatus for dry cleaning of fabrics and textiles without collection, purifying, and/or recirculation of the used solvent.

1 Claim, 1 Drawing Figure FIELD OF THE INVENTION This invention relates to apparatus for dry cleaning of fabrics.

BACKGROUND OF THE INVENTION Various equipment has been developed for applying hot solvents, usually aqueous, and/r steam to rugs, upholstery, drapes, and the like by means of handoperated nozzles which spray the cleaning fluid upon the fabric and then transport the contaminated solvent from the work to a collection vessel wherein the clean-' ing fluid may or may not be separated from the transported soil and recirculated. An example of such apparatus is disclosed in Thompson et al. US. Pat. No. 3,562,844. Such equipment, however, cannot be used with certain fabrics, requires a substantial drying period, and necessitates the use of bulky solvent collection or treatment chambers; Conventional commercial dry cleaning equipment has been developed to a high degree of efficiency. However, such equipment is large and expensive, requires the recirculation and purification of large quantities of expensive and s'ometirnes hazardous solvent and, normally, is limited to cleaning of items at the dry cleaning plant where the items are immersed in the dry cleaning solvent. Naturally such equipment is not adapted for portability or nonprofessional use. Thus, dry cleaning, as distinguished from washing and shampooing, of upholstery and drapes or curtains in place, or on the premises, has not been possible. Nor has the dry cleaning of clothing been possible, except by the sending of such clothing to professional dry cleaning'establishments.

Accordingly, it is an object of the present invention to provide a preferably portable, low-cost, safe, and highly efficient, yet operationally simple apparatus for the dry cleaning of fabricseither in dry cleaning establishments or elsewhere and without the necessity of collecting, purifying, and recirculating the solvent. 1

SUMMARY OF THE INVENTION This object and others are achieved by the apparatus herein disclosed and claimed in which a reservoir for dry cleaning solvent, powered liquid and suction pumps, a suction chamber, and a muffler are compactly mounted on a carriage or other support. A hand nozzle, for instance, of the type disclosed in the abovementioned US. Pat. No. 3,562,844, has a pair of chambers connected, respectively, with the outlets of the liquid pump and the suction chamber. The inlet of the Iiquid pump is connected. to the reservoir and the inlet of the suction pump is connected to the suction chamber, while the outlet of the suction pump discharges outside of the apparatus. The apparatus is designed for use with special dry cleaning solvent of relatively high volatility and solvency (cleaning power), and the liquid and suction pumps are designed in relation to these characteristics of the cleaning solvent and the resistance to flow of the liquid and suction systems so that the liquid solvent is sprayed against fabric confronting the nozzle and is quickly transported by suction into the suction chamber. The transported solvent is substantially completely vaporized within the suction duct and the suction chamber and is then exhausted through the suction pump to the outside of the apparatus. Dissolved and entrained soil collects within the suction chamber from which it may be periodically removed.

.BRIEF DESCRIPTIONOF THE DRAWING The accompanying drawing is a schematic representation of the novel apparatus.

DESCRIPTION OF THE PREFERRED EMBODIMENT The apparatus comprises a wheeled carriage 5 having upright end walls 6 and 7, a top wall 8, side walls, one being shown at 8a, and suitable access doors (not shown) completing an enclosure. Mounted on floor 5a is a motor 9 connected by wiring 10 through a switch 11 to a source of power symbolized at 12; A liquid pump 13, also conveniently mounted on the carriage, as by means of raised platform 5b, is driven from the motor by means of a belt 14 and has its inlet connected by a conduit 15 to a solvent, reservoir 16 mounted in the upper part of the carriage enclosure. The reservoir has a filling opening 17.

A suction pump 20 of the Roots type, mounted on the floor of the carriage, is driven from motor 9 by means of a belt 21 and has its inlet connected by a duct 22 to the upper portion of a suction chamber 23 secured to opposite end wall 7. The outlet of the suction pump is connected by a duct 24 to a muffler 25 shown mounted in the upper part of the carriage enclosure abreast of the solvent reservoir. An exhaust duct 26 leads from the muffler to the exterior of the apparatus. A control valve 27 is provided in a pipe 270 and has an actuating element 28. A meter 29 is also connected to pipe 27a. The purpose of valve 27 and meter 29 is to maintain a desired depression in vacuum chamber 23.

The outlet of liquid solvent pump 13 is connected by a conduit 32, a quick disconnect coupling 33, and a flexible tube 34 to a spray nozzle 35 disposed in a first chamber 36 in a hand tool 37 so as to spray solvent against confronting fabric. Nozzle 35 connects with tubing 34 through a short curved pipe 39 and a valve 40, which may be normally spring-closed and -opened by a hand actuator 41. A small branch pipe 42 leading from solvent conduit 32 has a valve 43 which is normally closed, but which may be opened to drain liquid from the system.

The upper part of vacuum chamber 23 is also connected by a suction hose 44 to a second chamber 45 in nozzle 37. Baffle 46 between chamber 36 and 45 has its lower edge spaced sufficiently above the confronting fabric to permit suction in chamber 45 to draw the sprayed solvent with dissolved and entrained soil from the fabric through hose 44 into the suction chamber. In the lower part of the suction chamber there is provided a cleanout opening 47 for periodical removal of collected solids and other substantially nonfluent and nonvaporizable material.

Liquid solvent discharge line 32, 34 is shown as running along the outside of suction hose 44 and secured enter the suction hose at that point. In either case, the high velocity fluid flow in the hose may tend to cool the liquid'in pipe 34 in an undesirable manner. in order to counteract this, a bypass 52 is attached to a tee 53 in the solvent line and extends into the upper part of solvent tank 16. At the upper end of the bypass there is provided a gooseneck 54 having a restricted outlet 55 into the solvent tank. A valve may be provided in the bypass to vary the restrictive effect thereof. The forcing of the solvent through the restriction 55 will result in translation of a portion of the energy applied to the liquid pump 13 into heat which will tend to raise the temperature of the solvent in tank 16. Obviously, the heat produced by this means will be increased as valve 40 near the exit end of the solvent line is closed. This will permit heating of the solvent in tank 16 before valve 40 is opened in order to begin the cleaning operation. Valve 40 also serves to adjust the spraying of liquid solvent to insure the desired cleaning and drying effect and, also, to cut off the supply of solvent in case it is desired to pass the nozzle over the previously sprayed area to enhance the drying action.

It is contemplated that the apparatus can be safely and effectively used in an inhabited enclosure which is not too restricted in size and during brief periods, as would be necessary in removing spots from fabrics or textiles, without removing them from the enclosure and even while remaining in place. Consequently, the nature of the solvent used and the careful designing of the pumps and fluid passages as well as the nozzle, in coordination therewith, are very critical. The solvent must be either of low cost so that large quantities of it may be used, or very efficient. It must soften or dissolve the soil or the binder holding the soil in the fabric and it must penetrate the fabric to facilitate removal of soils therefrom. Also, the solvent must prevent the solids from being redeposited in the fabric or in the hose, i.e., must carry such solids through the hose into the suction and waste chamber 23. This requires that the solvent remain substantially in liquid state until it enters the suction tank. Finally, it is essential for open use of the apparatus in a room that the solvent be nonflammable and nontoxic and also vaporizable under the conditions in the suction chamber so that soils will be dropped and only vapors and-gases will be discharged.

For adequate efficiency, the solvent must be infused into the fabric where it must quickly pick up soil and carry the same through the suction hose into the suction chamber. This requires a solvent of high K.B. value (Kauri Butanol value ASTM Method D 1133-61). Many solvents were potentially usable and many were tried. Some were rejected as flammable and/or highly toxic, as benzene; others, as ketones and esters, were known to attack certain fabrics, such as rayon, and pine-derived solvents were not sufficiently volatile. Of the chlorinated hydrocarbons used by commercial dry cleaners, carbon tetrachloride, ethylene dichloride, propylene dichloride, and monochlorobenzene were rejected as being too toxic for use in a non-circulating system of the present type. Methylene chloride was rejected as being too volatile.

From the list of materials tried, the most suitable solvents appear to be trichloroethane, perchloroethylene, and trichloroethylene. Of these three, trichloroethylene proved to be the most satisfactory from the points of view of solvency (K.B. value), evaporation rate, odor, nontoxicity, and general usability. Various additives and combinations of ingredients may be used for various purposes. For instance, an ingredient may be incorporated in the solvent which will cause deposition of stain or soil absorbing solid material in the work fabric. Combustibility inhibitors also may be called for. The strong air current across the fabric, induced by the suction in nozzle passage 45, will pick up soils and other solid material in the fabric, leaving the fabric substantially dry and clean, or requiring only a very short time to become fully dry.

The solids and nonevaporated liquids discharged into suction chamber 23 collect as a sludge in the bottom thereof and, from time to time, may be removed through plug opening 46.

Accordingly, the novel apparatus, utilizing surface cleaning as distinguished from immersion, is well adapted for use by professionals or nonprofessionals, for instance, within inhabited enclosures, for the prompt and effective removal of stains and spots, particularly where the sending of the work to a professional dry cleaning establishment is not convenient or possible. Even though the exhaust from outlet 26 may be piped outside, a certain small quantity of the solvent inevitably will escape from the hand tool so that the nontoxicity and nonflammability as well as the absence of unpleasant odor are imperative. Undoubtedly, other solvents will be found having the required characteristics and the field of solvents, of course, will be greatly expanded where required characteristics are less rigorous, possibly including mixtures of aqueous with dry cleaning solvents. The novel apparatus, emphasizing volatility and rapid cleaning properties of the solvent, is diametrically opposite to the emphasis in the commercial dry cleaning industry where large quantities of solvent are utilized in closed systems with various distilling and other purifying or filtering features to avoid wastage of the large quantities of solvent necessary. As stated, my present concept contemplates the use of relatively small quantities of quite volatile, highly efficient, safe solvent in an open or non-circulating system.

The invention may be modified in various respects as will occur to those skilled in the art, and the exclusive use of all modifications as come within the scope of the appended claims is contemplated.

I claim:

1. Cleaning apparatus capable of normal safe utilization of a nonaqueous dry cleaning solvent of predetermined volatility and solvency in surface cleaning of fabrics without recirculation of the used solvent, comprising a. a support carriage;

b. a reservoir for solvent and c. a suction chamber mounted on said carriage;

d. a work tool having a fabric confronting face and a chamber opening through said face for exposure to fabric to be cleaned;

e. powered liquid and f. suction pumps also mounted on said carriage;

g. a spray nozzle positioned to discharge solvent against said fabric;

h. first and second conduits connecting the inlet and outlet of said liquid pump, respectively, with said reservoir and said nozzle;

i. a first duct connecting the inlet of said suction pump serially with said suction chamber and said nozzle chamber;

5 6 j. a restricted bypass conduit extending fromsaid secsaid conduits and said ducts to cause spraying of nd liquid conduit upstream of said valve to said the solvent through said nozzle against the conreservoir, the discharge pressure in said liquid fronting fabric, picking up the sprayed solvent pump outlet, during operation of said pump, in rewith dissolved and entrained soil and transportlation to the restrictive effect of said bypass coning the same through said first duct to said sucduit being such as to produce substantial heating of tion chamber, and substantially complete vaporfluid in said conduit and said reservoir; and ization of the transported solvent in said first k. an exhaust duct leading from the outlet of said sucduct and said suction chamber whereby only subtion pump to the exterior of the apparatus; stantially nonvolatile residues are deposited in said liquid and suction pumps being designed in re- 0 said suction chamber and the vaporized solvent lation to the volatility and solvency characterisis discharged through said-exhaust duct. tics of said solvent and the flow resistances of 

1. Cleaning apparatus capable of normal safe utilization of a nonaqueous dry cleaning solvent of predetermined volatility and solvency in surface cleaning of fabrics without recirculation of the used solvent, comprising a. a support carriage; b. a reservoir for solvent and c. a suction chamber mounted on said carriage; d. a work tool having a fabric confronting face and a chamber opening through said face for exposure to fabric to be cleaned; e. powered liquid and f. suction pumps also mounted on said carriage; g. a spray nozzle positioned to discharge solvent against said fabric; h. first and second conduits connecting the inlet and outlet of said liquid pump, respectively, with said reservoir and said nozzle; i. a first duct connecting the inlet of said suction pump serially with said suction chamber and said nozzle chamber; j. a restricted bypass conduit extending from said second liquid conduit upstream of said valve to said reservoir, the discharge pressure in said liquid pump outlet, during operation of said pump, in relation to the restrictive effect of said bypass conduit being such as to produce substantial heating of fluid in said conduit and said reservoir; and k. an exhaust duct leading from the outlet of said suction pump to the exterior of the apparatus; said liquid and suction pumps being designed in relation to the volatility and solvency characteristics of said solvent and the flow resistances of said conduits and said ducts to cause spraying of the solvent through said nozzle against the confronting fabric, picking up the sprayed solvent with dissolved and entrained soil and transporting the same through said first duct to said suction chamber, and substantially complete vaporization of the transported solvent in said first duct and said suction chamber whereby only substantially nonvolatile residues are deposited in said suction chamber and the vaporized solvent is discharged through said exhaust duct. 